Beryllium Copper Wire (BeCu Wire) is a high-performance copper alloy wire containing approximately 0.5%–2% beryllium. After proper heat treatment, it becomes one of the strongest copper-based alloys available, combining high electrical conductivity with exceptional mechanical strength.
Beryllium copper wire is widely used in electronics, aerospace, automotive, precision instruments, and spring applications requiring outstanding fatigue resistance, dimensional stability, and non-sparking safety.
Chemical Composition (UNS C17200)
| Element | Typical % |
|---|---|
| Copper (Cu) | 97.5 – 98.5 |
| Beryllium (Be) | 1.8 – 2.0 |
| Cobalt / Nickel | 0.2 – 0.6 |
| Iron & Others | < 0.2 |
Note:
Even very small additions of beryllium dramatically increase copper’s strength
through precipitation hardening.
Key Physical Properties
| Property | Typical Value |
|---|---|
| Density | ~8.25 g/cm³ |
| Melting Range | 865 – 980°C |
| Electrical Conductivity | 22 – 60% IACS |
| Thermal Conductivity | ~105 – 210 W/m·K |
| Coefficient of Expansion | 17 × 10⁻⁶ /°C |
| Magnetic Behavior | Non-magnetic |
| Elastic Modulus | ~131 GPa |
Key Mechanical Properties (Peak Aged)
| Property | Typical Range |
|---|---|
| Tensile Strength | 1,100 – 1,400 MPa |
| Yield Strength | 1,000 – 1,200 MPa |
| Elongation | 1 – 5% |
| Hardness | 360 – 420 HV |
| Fatigue Strength | Excellent |
| Elastic Limit | Very High |
Comparison:
Beryllium copper wire is approximately 5–6× stronger than pure copper
while retaining useful electrical conductivity.
Strengthening & Metallurgical Behavior
✔ FCC copper matrix strengthened by fine beryllide precipitates
✔ Solution heat treatment followed by age hardening
✔ Optional cold work before aging for maximum strength
✔ Excellent spring properties and fatigue resistance
✔ Stable mechanical performance over long service life
Key Advantage:
Beryllium copper is one of the few copper alloys that can be precipitation hardened.
Key Characteristics of Beryllium Copper Wire
✔ Extremely high tensile and yield strength
✔ Excellent conductivity for a high-strength alloy
✔ Outstanding fatigue resistance
✔ Exceptional spring memory
✔ Non-sparking and non-magnetic
✔ High corrosion resistance
✔ Stable performance at elevated temperatures
Refining & Processing Properties
✔ High-purity copper alloying with controlled beryllium addition
✔ Wire drawing before final aging treatment
✔ Solution annealing and age hardening at ~315–325°C
✔ Precision processing required due to Be content
Safety Note:
Beryllium dust and fumes are hazardous during processing;
strict industrial safety controls are mandatory.
Available Forms
Fine and ultra-fine wire
Spring wire
Round, square, and flat wire
Coiled wire
Plated BeCu wire (tin, silver, nickel)
Annealed, cold-worked, or age-hardened tempers
Typical diameter range: 0.02 mm to 6 mm
Applications of Beryllium Copper Wire
Electrical & Electronics
Connector springs
Contacts and terminals
EMI/RFI shielding springs
Switch components
Aerospace & Defense
Precision springs
Electrical contacts
Guidance and sensor systems
Automotive & EV
Battery contacts
Relay springs
Control modules
Oil, Gas & Hazardous Areas
Non-sparking components
Safety wiring
Intrinsically safe systems
Precision Engineering
Watch springs
Medical device components
Instrumentation springs
Advantages of Beryllium Copper Wire
✔ Highest strength among copper alloys
✔ Long fatigue life
✔ Excellent spring properties
✔ Good electrical and thermal conductivity
✔ Safe for explosive environments
✔ Excellent corrosion resistance
Why Choose Beryllium Copper Wire?
Choose Beryllium Copper Wire when your application demands extreme strength, spring performance with conductivity, long-term fatigue reliability, non-sparking safety, and high dimensional precision.
Engineering Recommendation:
When phosphor bronze or brass fails under fatigue or load,
beryllium copper wire is the premium solution.
Comparison with Other Copper Alloy Wires
| Property | BeCu | Phosphor Bronze | Brass |
|---|---|---|---|
| Tensile Strength | ★★★★★ | ★★★ | ★★ |
| Fatigue Resistance | ★★★★★ | ★★★ | ★★ |
| Conductivity | ★★★ | ★★★★ | ★★★ |
| Spring Performance | ★★★★★ | ★★★ | ★★ |
| Cost | ★★ | ★★★★ | ★★★★★ |
Sustainability & Lifecycle
✔ Long service life reduces replacement frequency
✔ Fully recyclable as a copper alloy
✔ Higher upfront cost but lower lifecycle cost